The 24-year-old “Slow Hands” singer and the 21-year-old “Let Me Go” crooner were spotted at a Backstreet Boys concert together on Saturday night (February 17) in the Axis Theater’s VIP section at Planet Hollywood Resort and Casino in Las Vegas.

The footage was captured by a fan, ninergrl6, on Twitter. The fan posted videos of the duo dancing, singing, and goofing around with each other during the show.

In the videos, both Niall and Hailee can be seen jamming out to “I Want It That Way.” A.J. McLean even approaches Niall and sings with him!

Hailee wore a plunging black shirt and jeans, while Niall opted for a plaid shirt and jeans.

A source told E! News that the pair headed to XS Nightclub after the concert, sitting together at a table with a few friends, sipping on Absolut Elyx cocktails, and listening to Diplo‘s DJ set.

“She’s not actively pursuing anything,” a source added to People. “Niall is really into her but she’s unsure if she wants to get into something new right away. They’ve been friends for a long, long time and are very comfortable with each other, but it’s nothing serious right now.”